System for installing and retrieving well tools in well strings



A ril 4, 1967 SYSTEM FOR INSTALLING AND RETRIEVING WELL TOOLS IN WELLSTRINGS Filed June 30, 1964 5 Sheets-Sheet l INVENTORI EDWARD D. YETMAN8 w/o m HIS ATTORNEY E. 1;. YETMAN 3,312,283

E. D. YETMAN SYSTEM FOR INSTALLING AND RETRIEVING WELL TOOLS IN WELLSTRINGS April 4, 1967 5 Sheets-Sheet 2 Filed June 30, 1964 FIG. 20

FIG. 2B

INVENTORZ EDWARD D. YETMAN BY: d

HIS ATTORNEY April 4, 1967 E. D. YETMAN SYSTEM FOR INSTALLING ANDRETRIEVING WELL TOOLS IN WELL STRINGS Filed June 30, 1964 5 Sheets-Sheet3 mmwmmwmwwe a H1. gllnllrillillil u. h n o n a w u I llr FIG. 2D

MME QwMEB M INVENTORI EDWARD o. YETMAN HIS ATTORNEY April 4, 1967 FiledJune 30, 1964 E D. YETMAN SYSTEM FOR II ISTALLING AND RETRIEVING WELLTOOLS IN WELL STRINGS 5 Sheets-Sheet '4.

INVENTORI EDWARD D. YETMAN W/MW HIS ATTORNEY April 4, 1967 E. D. YETMANSYSTEM FOR INSTALLING AND RETRIEVING WELL TOOLS IN WELL STRINGS FiledJune 30, 1964 FIG. 68

5 Sheets-Sheet 5 INVENTORZ EDWARD D. YETMAN HIS ATTORNEY United StatesPatent Qfitice 3,312,283 Patented Apr. 4, 1967 3 312,283 SYSTEM FORINSTALLING AND RETRIEVING WELL TOOLS IN WELL STRINGS Edward D. Yetman,Bakersfield, Calif., assignor to Shell Oil Company, New York, N .Y., acorporation of Delaware Filed June 30, 1964, Ser. No. 379,301 7 Claims.(Cl. 16646) This invention relates to a method and apparatus for runningwell tools into and out of Well strings. More particularly, theinvention is directed to a means for installing and retrieving welltools in well strings disposed in underwater wells. The invention hasspecific application to the running in and retrieving of well tools fromside pockets disposed at locations within well strings that areinaccessible to conventional running in and retrieving apparatus.

The invention is particularly directed to the insertion of a tool, suchas a gas-lift valve, in a preselected pocket of a series ofsubstantially identical laterally disposed pockets extending from thesides of a well production string at axially spaced intervalstherealong. The invention provides means whereby an insertion orretrieving mechanism may be pumped through a production string to apreselected pocket and there be activated to insert a tool into saidpocket, or retrieve a tool from said pocket. The insertion or retrievingmechanisms are carried by a carrier of suflicient flexibility to passthrough curved flow lines and/or wellhead conduits leading to theproduction or tubing string.

The invention is especially suited for the th-roughtheflowline operationof underwater wells. Through-theflowline operations refer to techniqueswherein Well completion and operation procedures are conducted through aflo-Wline communicating with a surface location, such as an operatingstation, and a submerged well installation. With such techniques, asubmerged well can be equipped initially with facilities that will allowmaintenance of production via the existing closed system for the life ofthe well without the use of wire line tools or workover rigs. A primerequirement of such technique-s is the ability to select and land toolsat will in any of several locations within a tubing string. The presentinvention was developed with this object in mind and has provedparticularly suitable for inserting tools, such as gas-lift valves, inone of a preselected series of substantially identical tool-receivingpositions within a well string. The invention provides means whereby aninstallation mechanism may be pumped into and through a well string to apreselected position where it can be activated to install a tool securedthereto inplace. The invention also provides means whereby a tool soinstalled can be similarly retrieved.

The invention promises to be particularly valuable in the recentunderwater completion procedures being used by the oil industry inoffshore locations. In these procedures, both the wellhead assembliesand production control units are positioned beneath the surface of thewater and preferably close to the bottom of the water. Positioningwellhead assemblies and control units in this manner has the advantagethat it does not present navigation hazards, nor is it subject to thecorrosive action of salt water spray and air, as are assembliesextending above the water. In addition, positioning wellhead assembliesand production control units at the bottom of the ocean results inconsiderable savings, since it is not necessary to erect protectivestationary platforms around the wellheads in depths are encounteredwhich make it infeasible to extend structures from the floor of theocean to the surface.

The placement of wellhead assemblies on the ocean floor raises newproblems with regard to carrying out workover, maintenance, or otheroperations in completed wells. Major w-orhover operations call for theuse of an operating station in the form of a barge, platform or vesselpositioned on the surface of the water above the well, together withequipment for going down and entering the wellhead assembly and thetubing and/or casing string connected thereto, and in some instances mayrequire the entire removal of the wellhead assembly to the surface. Inorder to carry out some of the more simple workover or maintenanceoperations, such as the perforation of well casings, the removal orinsertion of a valve, the cleaning of parafiin from a tubing string,etc., it has been necessary to develop an entirely new line of welltools which can be pumped through a well string from some remotelocation often a mile or more from the well. Upon entering the well withsuch tools, the tool passing through the well string is positionedtherein for carrying out some preselected operation. After completingthe operation, the tool in the well string is removed, generally byreverse circulation.

While the problems encountered in pumping a tool to the bottom of thewell tubing string, or to a single stop shoulder, are fairly readilysolved, the problems encountered in pumping a tool to a preselectedposition intermediate a series of similar positions is far moredifficult. This is especially true where it is necessary to position atool in a selected one of a series of identical locations locatedlongitudinally alongthe well string. Such positioning, of necessity,requires an accurate locating or indexing system adapted forthroughthe-flowline use in the curved flowlines generally used tocommunicate with underwater installations.

.In the past, well tools, such as gas-lift valves, have been run int-oselected positions in well strings through means of wireline device'sextending to the top of the well. Such devices were generally loweredinto the well string on a wireline and activated by said wireline at aselected depth to force the tool carried by the line into a selectedpocket or mandrel. In this case, the length of the wireline run into thewell string indicated the depth of the tool within the well string andforces imparted through the wireline at selected depths were utilized toactivate a seating mechanism secured to the wireline and operativelyengaging a tool carried thereby.

Wireline systems have proved effective when used in land-based wellshaving relatively straight strings extending into the earth. In suchwells, tools secured to the wireline descend directly down the wellstring by virtue of their weight and the weight of the wireline. Theenvironment surrounding offshore wells is, however, critically differentfrom that of land-based wells. In offshore wells, wherein the wellheadassemblies are disposed on the bottom of the ocean, the line ofcommunication between the well and the cooperating surface or possiblyunderwater operating or workover station includes lengths of flowlineextending between the station and the wellhead assembly. For example,the flowlines may run along the bottom of the ocean to a stationdisposed thereon, remote from the wellhead assembly. These flowlines areflexible to some extent, and generally include curves of varying degreesto compensate for irregularities on the ocean floor. It is believedapparent that the reliance of tool weight to impart movement through acurved flowline will result in the hanging up of the tool in the curvedand horizontal sections of the flowline and in fouling of the wirelinesecured to the tool.

Previous systems used to place gas-lift valves in side pockets ormandrels relied upon different shaped or sized pockets or mandrels tointeract with the indexing mechanism in order to insure that the valvewas placed in the proper pocket or mandrel. Such systems severely limitthe number of positioning mandrels that may be located in a well string,and are expensive to fabricate and maintain since they prevent the useof a uniform side pocket or mandrel. Furthermore, the kickover orexpansion mechanism used in previous systems to place the gas-lift valvein the side pocket or mandrel was free to actuate at all side pocketlocations prior to coming into contact with the preselected location atwhich it was to be permanently positioned. As a result, the gas-liftvalves were often damaged before reaching the preselected pocketormandrel within the well string.

Thus, the need for a tool carrier adapted to pass through curvedflowlines extending into underwater well strings and position a toolwithin a preselected side pocket of a series of identical pocketslocated in the well strings is apparent. I

It is therefore an object of the present invention to provide a systemto pass well tools through a well string into preselected pockets ormandrels disposed in communication therewith. Another object of theinvention is to provide a flexible apparatus adapted to be pumpedthrough curved and horizontal sections of flowlines communicating with awell string. In this respect, it is a more specific object of theinvention to provide flexible coupling means to secure such an apparatustogether for movement through curved sections of a flowline.

A further object of the invention is to provide an apparatus adapted topass through a well string and automatically install a tool securedthereto in one preselected pocket of a plurality of identical pocketsdisposed laterally along the well string. In this respect, it is anotherobject of the invention to provide an installation mechanism adapted tobe selectively operated by said apparatus to lock the tool desired to belocated in the preselected mandrel.

Yet another object of the invention is to provide a well tool carrieradapted to run tool installation and removal means through a well stringto a preselected position therein. In relation to this object, it isanother object to provide said carrier with means to selectively releaseand remove the tool from the preselected position.

These and other objects of this invention will become apparent from thefollowing description and accompany ing illustrations of the invention.Broadly, the present invention provides a system for installing andremoving well tools in preselected identical pockets disposed laterallyof and in communication with the interior of a well string. The systemincludes identical indexing areas located within the conduit at each ofthe pockets. The latter areas are identical to each other in internaldiameter, but have a diameter diiferent from the internal diameter ofthe conduit. The system further in cludes a carrier operatively engagingthe tool to propel it through the conduit and a selectively operableinstallation mechanism secured to the tool and adapted to be activatedto install it in the preselected pocket. An indexing device isoperatively secured to the installation mechanism and carries a sensingmeans cooperable with the indexing areas within the conduit to sense thenumber of such areas through which the indexing device is passed. Theindexing device also carries an actuator cooperable with the sensingmeans to activate the installation mechanism and thus install the toolin the desired preselected tool receiving position.

More specifically, the installation mechanism of the above describedsystem comprises a housing member adapted to be secured to the tool andpropelled therewith through the conduit. Selectively operable throw-overmeans are operatively associated with the installation mechanism toautomatically bias a tool connected thereto into alignment with thepreselected tool pocket. In addition to being used as an installationmeans, the apparatus of the present invention may be used to retrievetools from pockets disposed in well strings.

The invention will now be described with reference to the accompanyingdrawings wherein:

FIGURE 1 is a schematic view diagrammatically illustrating an underwaterwellhead assembly having a pair of tubing strings extending downwardlytherefrom;

FIGURES 2A, 2B, 2C, 2D and 2E are partial sectional or elevation viewsof the through-the-fiowline insertion assembly of. the invention;

FIGURE 3 is an exploded view of the indexing device, illustrated inFIGURE 2C, with certain retaining elements omitted therefrom for thesake of clarity;

FIGURE 4 is a respective view of the actuating rod of the FIGURE 3device;

FIGURE 5 is a sectional view showing the throw-over means of theinstallation mechanism of FIGURE 2D in an expanded position;

FIGURES 6A and 6B are diagrammatic sectional views of a well stringillustrating the application of the invention in the insertion of agas-lift valve into a mandrel disposed in a side pocket of a wellstring;

FIGURES 7A :and 7B are diagrammatic sectional views corresponding toFIGURES 6A and 6B, illustrating the application of the invention in theremoval of a gaslift valve from a mandrel disposed in a side pocket of awvell string;

FIGURE 8 is a longitudinal sectional view of an indexing nipple adaptedto be assembled in the well string as an indexing area; and

FIGURE 9 is a longitudinal sectional view illustrating a plunger headadapted to be used in a retrieving operation.

Referring to FIGURE 1 of the drawings, a wellhead assembly is shown asbeing positioned below the surface 11 of a body of water and preferablyon the ocean floor 12. .The wellhead apparatus comprises a platform 13secured to the top of a conductor pipe or surface casing 14- which inturn extends into the earth below the body of water and is preferablycemented therein in a conventional manner. The wellhead assembly mayalso be provided with two or more vertically positioned guide columns 15and 16 which are fixedly secured at their lower ends to the platform 13.A well casinghead 17 is mounted on the top of the conductor pipe 14 anda control equipment housing 18 closes the top of the casinghead and/orany casing and tubing suspension equipment employed on the wellheadassembly, as well as the various control valves and other controlequipment normally used on the top of a well of this type.

Emerging from the housing 18 is a pair of flowlines 20 and 21 whichpreferably bend in long sweeping curves from a vertical position down toa substantially horizontal position so that they can run along the oceanfloor to a remote location where fluid from the well, and normally fromother wells, is collected and metered and treated. Such a collectionstation may be several miles away. During the production of the well,normally only one of the flowlines 20 or 21 is employed in transportingfluid away from the well. The well may be provided with one or morestrings of well casing 22 suspended within the conductor pipe 14. Theflowlines 20 and 21 in the particular installation illustrated are incommunication with and formcontinuations of a pair of tubing strings 23and 24 depending within the well. However, in other installationsutilizing a single tubing string, the second flowline may be incommunication with the annular space between the tubing strings and theadjacent wellhead. Further, more than two flowlines may be used. Thetubing string 24 is provided with a plurality of indexing nipples 25spacedlongitudinally along the string. Although only two indexingnipples are illustrated, it is to be understood that this number may beincreased without departing from the invention. The tubing string 24further includes a series of valve housings or side pockets 26 spacedtherealong wherein gas-lift valves may be positioned. The detailedstructure and operation of the indexing nipples 25 and side pockets 26will be developed subsequently.

Referring now to FIGURES 2A, 2B, 2C, 2D and 2E, there is illustratetdthe assembly adapted to run tools, such as a gas-lift valve, from acollection station through the flowline 21 into selected side pockets 26in the tubing string 24. The assembly includes a pair of spaced toolcarriers 28 and 38 joined together through a flexible member shown ascable 36. The tool carrier 28 (FIGURE 2A) comprises a central mandrelhaving sections 29 and 30 with axially spaced sealing elements orpackers 32 and 33 mounted thereon. Packers 32 and 33 may be made ofrubber or certain plastic materials. Preferably a ball-insocket joint 31joins sections 29 and 30 together so as to facilitate movement of thetool carrier 28 in curved sections of the flowline. Fliud ports 34 and35 are provided through the walls of sections 29 and 30 so that fluidmay enter the inside of the packers 32 and 33 to inflate and sealinglyexpand them against the inner walls of tubing string 24. The toolcarrier 38 is in all respects identical with tool carrier 28 andelements 39-45 of carrier 38 correspond to the elements 2935 of thepreviously described carrier 28. The exact internal details of the toolcarriers 28 and 38 are not the subject of this invention and may takeany suitable form such as that shown in US. Patent No. 3,052,302 toLagucki or U.S. Patent No. 3,050,130 to Culver et al.

During use of the tool carrier 28, a pressure fluid enters port 34 sothat packer element 32 is forced against the inner wall of tubing spring24, thus causing the packer element to act as a piston, whereby the toolcarrier 28 is forced downwardly through the tubing string 27. Thus, itmay be seen that, on the downward travel of the present tool carrier 28the upper sealing cement 32 maintains a tight fit against the tubingstring 24 at all times, while the lower sealing element 33 is idle andmerely acts as an inoperative piston which would not contact the tubingwall 24 with any force to form a seal thereagainst. The tool carrier 38is necessary because the tool carrier 28 loses its sealing contact withthe wall of tubing string 24 in areas of enlarged diameter, such as theside pocket locations 26, and the carrier 28 can no longer be forceddownward by the driving fluid. The stiff, lightweight cable 36 providedbetween the tool carriers 28 and 38 is of sufficient length to span theenlarged-diameter portions of the tubing string 24 such as areencountered at side pockets 26 and, as a result, one of the toolcarriers 28 or 38 is always in sealing engagement with a normal-diameterportion of the tubing string 24. A fishinghead 37 is secured to theupper end of tool carrier 28 in order to facilitate removal of thecarriers and any elements secured thereto should they become fouledwithin the tubing string 24.

The mandrel section 40 of tool carrier 38 is joined to an indexingmechanism 47 through a double ball-joint assembly 50. The sole purposeof the indexing mechanism, as will be developed subsequently, is toselectively operate an installation mechanism 51 (FIGURE 2D) secured tothe indexing mechanism 47 through a double ball-joint connection 52. Thedouble ball-joint connection 52 has a flexible cable 53 extendingtherethrough and into the installation mechanism 51. This cable, as willbe developed in detail subsequently, has one end secured to theactuating rod 54 of the indexing mechanism 47 and the other end securedto a retaining probe 55 (FIGURE 2D) in the installation mechanism 51through means of a stop 58.

Reference is now made to the detailed structure of the indexingmechanism 47, illustrated in vertical section in FIGURE 2C and inperspective in FIGURES 3 and 4. The mechanism comprises a housingsection 62 fabricated of several joined tubular sections and havinghoused therein the elements of the mechanism, including the previouslymentioned actuating rod 54. The rod 54, as illustrated in full in FIGURE4, is a unitary structure and extends through substantially the entirelength of the housing section 62. At this point, it is noted that therod 54 is of stepped configuration and includes an enlarged actuatingportion 63 and a grooved portion 64 adapted to cooperate with theinternal structure of the indexing mechanism, as will be developedsubsequently The remaining portions of the rod 54 are substantiallyequivalent, including the upper and lower ends thereof fixedly securedto a cap member 65 and a retention collar 66, respectively, as by screwthreads. As shown in FIGURE 2C, the rod 54 is slidably received in thehousing section 62 and is resiliently urged upwardly therein by acompression coil spring 67 interposed between the cap member 65 and thehousing section. In the illustrated position, upward movement of the rodis restrained by four retention dogs 70 pivotally secured to the housingsection 62 at pivots 71 and having hooked ends 72 urged into lockedengagement with the retention collar 66 by compression coil springs 73.It is noted that the exterior sides of the dogs 70 include rollers orfollowers 74 extending laterally out of the housing section 62. Throughthese rollers the dogs 70 are pivoted about the piVOts 71 when themechanism passes through an area of sufiiciently reduced diameter, thusreleasing the retention collar 66 and permitting the rod 54 to moveunder the action of the spring 67. It is noted that the dogs 70 aredesigned so that they must all be released simultaneously in order torelease the retention collar 66. Thus, the collar can only be releasedupon simultaneous passing of all of the rollers 74 through an area ofreduced diameter.

Upward movement of the rod 54 is normally limited by latching arm 75(FIGURE 3) having an arcuate end 76 received in the grooved portion 64.The latching arm 75, as will be developed in detail subsequently, isresiliently urged into engagement with the rod 54 and is adapted to beselectively swung out of this engaged position to release the rod. Whenthe latching arm 75 is engaged in the grooved portion 64 and the dogs 70are released, the rod 54 moves upwardly by a distance approximatelyequal to the length of the grooved portion 64. Abutment of the arcuateend 76 with the lower shoulder of the grooved portion 64 thus restrictsupward movement of the rod. When the rod 54 is at the upper extremity ofmovement, as limited by the grooved portion 64, the cap 65 is forcedinto a position where it holds four restoring dogs 77 in a substantiallyhorizontal position. In this position, the rearward ends of the dogs 77extend laterally from the housing section 62 to a slight extent At thesame time, the inner ends of the dogs are continuously biased downwardlyby leaf springs 80 interposed between the housing section and the uppersides of the dogs. It

I is noted that the springs 80 merely function to bias the dogs 77inwardly about the pivots 81 on which they are mounted and that thisbiasing force is insufficient to compress the spring 67. With the dogs77 in the substantially horizontal position, movement of the dogsthrough an area of reduced diameter will function to pivot the dogsinwardly, thus forcing the inner ends of the dogs against the cap 65. Asthe dogs are forced against the cap 65, the shaft 54 is forceddownwardly to a position wherein the dogs 70 may re-engage the retentioncollar 66, thus restoring the shaft to its initial position At thispoint it is noted that the laterally extended ends of the dogs 77 andthe extended rollers 74 of the dogs 70 are designed so as to becompressed by like areas of reduced diameter. Thus, a reduced diameterwhich functions to compress the rollers 74 will also function to pivotthe dogs 77 about the pivots 81. Through this arrangement,

the shaft 54 moves both upwardly and downwardly within the housingsection 62 when the section passes through an area of sufficientlyreduced diameter. This arrangement, as will be developed subsequently,functions to activate sensing or counting means within the indexingmechanism.

The internal structure of the indexing mechanism will now be describedwith reference to FIGURES 2C and 3. This structure includes fixed orstationary elements comprising a latching arm bearing plate 82, alatching arm spacer plate 83, a latching arm backing plate 34, a spacerplate 85, and a ratchet backup plate 86. The plates 82456 are rigidlyjoined by spacer bars 87 secured thereto within rectangular-shapedperipheral slots illustrated in FIGURE 3. In addition to securing theplates together, the spacer bars 07 secure the assembled plates withinthe housing section 62. The latter function is accomplished by securingthe lowermost ends of the spacer bars in recessed slots 90 formed in theexternal surface of an externally threaded nipple 91 threadably engagingan extension of the housing section 62. It is noted that the nipple 91is formed as a unitary member having threads on both ends thereof, withthe upper of said ends acting as a receiver for the extension of thehousing section 62 and the lower of said ends acting as a receiver forthe section of the indexing mechanism carrying the retention dogs 70.Although only two of the spacer bars 87 are illustrated in FIGURE 2C, itis to be understood that the mechanism includes four such bars, each ofwhich is received in one of the rectangularshaped peripheral recessesformed in the plates 82-86 illustrated in FIGURE 3.

The latching arm 75, referred to previously, is pivotally securedbetween the plates 02 and 04 by a dowel 92 extending between saidplates. The arm 75 is urged in a clockwise direction through means of apin 93 fixed thereto and extending slidably through a slot 94 in the endof a plate 82, which pin is resiliently contacted by a leaf spring 95carried by the dowel 92. A second releasing or disengaging pin 96 isfixed to the upper side of the arm 75 and extends slidably through aslot 97 in the latching arm backing plate 84. The latter pin, as will bedeveloped in detail subsequently, is disposed so as to be selectivelycontacted to urge the arm 75 in a counterclockwise direction, thusremoving it from the grooved portion 64 in the actuating rod 54.

Counter-clockwise movement is selectively imparted to the pin 96 and theattached latching arm 75 through an index plate 100 mounted forconcentric movement about the rod 54. A finger 101 is fixed to the plate100 and positioned so as to move in a path wherein it will abut againstthe pin 96 upon rotation of the plate 100. Thus, upon clockwise movementof the plate 100 the finger 101 will butt against the pin 96 and pivotthe latching arm 75 out of engagement with the grooved portion 64 of theactuating rod. The plate 100 is mounted for pivotal movement withrespect to the plate 85 through means of a drum 102 extending slidablythrough the plate 85 for rotational movement with respect thereto.Through means of a shoulder 103 formed thereon and dimensioned toslidably engage the plate 85, the drum 1102 also functions to positionthe index plate 100 between the plates 84 and 85. The drum 102 and theindexing plate 100 secured thereto are resiliently urged in a clockwisedirection by a coil spring 104 having one end received in an opening 105in the drum and the other end received in an opening 106 in the fixedspacer plate 85.

Rotational movement imparted to the drum 102 through the spring 104 iscontrolled through means of a ratchet drum 107 received on the upper endof the drum 102 for concentric movement with respect thereto in onedirection. Movement of the drum 107 with respect to the drum 102 islimited to one direction through means of resiliently biased pawls 110,111 and 112 mounted on the lower surface of the drum 107 for engagementwith ratchet teeth 113 formed on the outer surface of the drum 102. Thepawls -112 are of relatively conventional nature and comprise a toothsection secured to a resilient leaf section. The pawls are mounted sothat the leaf sections thereof are backed up, thus resiliently urgingthe tooth sections into contact with the cooperating ratchet teeth 113.It is noted, that in the assembled position, the teeth on the pawls110-112 assume an aligned relationship with the ratchet teeth 113.Through the ratchet and pawl arrangement on the drums 102 and 107, thespring 104 functions to turn the drums 102 and 107 clockwise as a unit.However, through the ratchet arrangement, the drum 102 may always bemanually turned counter-clockwise with respect to the drum 107.

Referring now to the control means adapted to selectively limit theclockwise rotation that may be imparted to the drums 102 and 107 throughthe spring 104. This means comprises a ratchet cage 114 mounted on theratchet backup plate 86 for slidable movement with respect theretothrough means of guide bolts or dowels 115 extending slidably throughthe cage 114 into threaded engagement with the plate 86. The cage 114 isresiliently urged away from the plate 86 by a compression coil spring116 interposed therebetween in concentric relationship with respect tothe rod 54. The actuating portion 63 on the rod 54 is dimensioned so asto abut against the cage 114 on downward movement of the rod withrespect to the cage. However, the diameter of the rod 54 below theactuating portion 63 is sufiiciently reduced to freely slide through thecage 114. Thus, downward movement of the rod 54 forces the cage 114toward the plate 86 and upward movement of the rod permits the spring116 to force the cage away from the plate 86. The cage 114 furtherincludes short ratchet fingers 117 and 120 and long ratchet fingers 121and 122 fixedly secured thereto and extending slidably throughperipheral slots in the plate 86. These fingers are positioned so as toselectively engage the ratchet teeth 123 on the drum 107, as will bedeveloped in the subsequent description of the ratchet operation.

In operation, the spring-loaded ratchet cage 114 moves up or down on theguide bolts 115 during travel of the actuating portion 63 of the rod 54.When the cage is moved downwardly, the ratchet teeth 123 are engaged bythe long fingers 121 and 122 at the outset, but are released by thesefingers when slots 124 and 125 formed in the respective long fingersassume an aligned relationship with the ratchet teeth 123. At thispoint, the ratchet teeth 123 are released and the drums 107 and 102 moveclockwise through 15 degrees, at which point the ratchet teeth 123engage the ends of the short fingers 117 and 120. When the actuatingportion 63 moves upwardly, the spring 116 forces the cage 114 up, thuswithdrawing the short fingers 117 and 120 from the ratchet 123 infreeing the drum 107 for clockwise movement through 15 degrees, at whichpoint the long fingers 121 and 122 re-engage the ratchet 123. Hence, thedrums 107 and 102 move 30 degrees clockwise each time the rod 54 movesup and down, as when the previously described dogs 70 and 77 encounteran area of reduced diameter. It is noted that, although the describedratchet arrangement limits the indexing mechanism to twelve counts(i.e., 12 up and down movements of the rod 54), the ratchet arrangementcould be modified within the scope of the invention to vary the numberof such counts which the mechanism is capable of handling.

From the above description, it can be seen that as the ratchet drum 107moves, so does the finger 101 on the index plate 100. The position ofthe drum 107 with respect to the index plate 100 can be adjusted byrotating the drum 102 with respect to the drum 107. Through thisadjustment, the number of counts (i.e., up and down movements of the rod54) required to turn the indexing plate 100 to a position where it willrelease the latching arm 75 can be adjusted. The number of countsinstalled by rotating the drum 102 with respect to the drum 107 can besensed by listening to the click of the pawls 110- 112 on the ratchetteeth 113 and can be substantiated through means of indexing markings126 on the indexing plate 100 and the indexing pointer 127 on the plate85. Thus, in operation, after the installed counts have been expended,the finger 101 engages the releasing pin 96 on'the latching arm 75.Preferably, the counting arrangement is designed so that the latchingarm is moved by the finger 101 when the rod moves downwardly. Thisreduces the force required to move the arm 75 to the small value of thespring force imparted by the spring 95, because the spring load on therod 54 is carried by the aforedescribed restoring dogs 77. With thelatching arm 75 out 'of its restrictive position in the grooved portion64, the rod 54 is free to travel to the upper extremity of the indexingtool the next time the retention dogs 70 are released. When this rodmovement occurs, the cable 53 is pulled upwardly along with the probe 55and the cap 65 rotates the restoring dogs 77 to a position where theiractivating surfaces are below the outside diameter of the housingsection 62. The pulling of the probe 55, in turn, functions to activatethe installation mechanism 51 and thus position the gas-lift valve 69,as will be developed in detail subsequently.

Reference is now made to the detailed structure of the installationmechanism 51 illustrated in FIGURES 2D and 5. This structure comprises atubular housing 130 having throw-over means 56 mounted thereon with thelower end of the housing 130 connected to the tool, in this in stance agas-lift valve 69, through means of a flexible joint 60 and a break-awaymechanism 61 mounted in the top of the gas-lift valve 69. The throw-overmechanism 56 comprises toggle links 131 pivotally secured to a sleeve132 which is slidable within the tubular housing 130 and is biasedupwardly by contact of the coil spring 133 with the outwardly flangedportion 132a of the sleeve 132. The toggle links 134 are pivotallysecured to the free ends of the links 131 and extend into pivotalengagement with the housing 130. The throw-over mechanism 56 furtherincludes a plurality of small dogs 135 which are pivotally mounted onthe sleeve 132 and are biased by leaf springs 136 to swing radiallyinward out of engagement with housing 130. As shown in FIGURE 2D, theprobe 55 prevents the dogs 135 from swinging inwardly out of engagementwith the housing 130 and thus prevents the sleeve 132 from slidingupwardly into the housing 130 under the action of coil spring 133.However, when the probe 55 is pulled upwardly, as shown in FIGURE 5, thedogs 135 swing inwardly out of engagement with housing 130 and thesleeve 132 begins to move upwardly under the pressure of coil spring133. As the spring-biased sleeve 132 moves upwardly, it forces thepivotally connected ends of the toggle links into engagement with thewalls of the conduit, such as the tubing string 24, through which thethrow-over mechanism 56 is passing and functions to force the throw-overmechanism and any structure secured thereto toward and into recessesencountered in the conduit. Thus, as shown in FIGURE 6B, the throw-overmechanism 56 has expanded to force the gas-lift valve 69 into aside-pocket 26.

The slidable sleeve 132, as illustrated in FIGURES 2D and terminates ina ball 139 which has a plunger 140 pivotally mounted thereon. Theplunger 140 extends downwardly into the interior of the gas-lift valve69 and has an enlarged head portion 141 threadably secured on itslowermost end. The enlarged head 141 prevents the upper ends of aplurality of spring-biased dogs 142, pivotally mounted on the valve 69,from swinging radially outwardly. However, when the sleeve 132 movesupwardly after the probe 55 has been pulled, the plunger head 141 alsomoves upwardly out of engagement with dogs 142 16 and the tops of thedogs are free to swing outwardly (see FIGURE 5 As illustrated in FIGURES2D and 5, the joint 60 includes a first annular flange 143 fixed to thelower end of the tubular housing 130 and a second annular flange 147fixed to the upper end of body member 146 of the breakaway mechanism 61.The coil spring 144, while not an essential element, tends to increasethe rigidity of the joint by urging the annular flanges 143 and 147 awayfrom each other. The flanges 143 and 147 are dimensioned so as to beloosely received within a cylindrical section 145, thus maximizing theflexibility of the elements joined thereby. The flexible joint 60facilitates passage of the V apparatus through curved sections of theflow line.

Attached to the upper end of the gas-lift valve 69 there is shown(FIGURES 2D and 5) a break-away mechanism, generally indicated at 61,adapted to be disconnected from the gas-lift valve 69 after the latterhas been run into one of the side pockets 26. A preferred form ofbreak-away mechanism comprises a body member 146 having a split springlocking ring 149 carried on a downwardly and outwardly tapered shoulder150 formed on the outward side of thebody 146. The normal diameter ofthe split spring locking ring 149 is of a size to contact a shoulder 154(at the top of gas-lift valve 69) when moved against it in an upwarddirection. At the same time the split spring locking ring 149 may becontracted sufficiently to pass the shoulder 154 when moving downwardlytherethrough. Just below the tapered shoulder 150 is a downwardlyslidable ring 151 pinned in place by shear pins 152 to the body 146 ofthe break-away mechanism 61. A retaining ring 153 is provided within anannular recess below the shear pin ring 151 for holding the latter onthe body 146 after the shear pins 152 have been sheared. The externaldiameter of the shear pin ring 151 is slightly greater than that of thewidest part of the tapered shoulder 150, so that on being forceddownwardly the locking spring ring 149 will contact the top of the shearpin ring 151.

Referring now to FIGURES 6A and 6B, a section of the tubing string 24 isshown having an indexing nipple 25 positioned above a side pocket 26disposed in the wall of the tubing string. Although the well casing 22is not illustrated throughout these figures of the drawings, it is to beunderstood that it would generally assume a position corresponding tothat shown in FIGURE 1. Furthermore, although the following descriptionis directed to the illustrated section of the tubing string 24, anindexing nipple 25, and a side pocket 26 thereof, the description isequally applicable to any section of the string 24 having an indexingnipple and a side pocket disposed therein.

As best shown in FIGURE 8, the indexing nipple 25 in cludes aninternally stepped upper section 162 and an externally stepped lowersection 163 dimensioned to be secured to a conduit, such as the tubingstring 24, into which the nipple is assembled. Sections 164 and 165 areformed in the upper and lower portions, respectively, of

' the nipple 25 and are equal in size to the internal diameter of theconduit 24-into which the nipple is assembled. Intermediate of thesections 164 and the internal surface of the nipple converges throughsmoothly tapered sections 166 and 167 to a reduced diameter countingarea 170. The counting area 170 is of a diameter sufiiciently small toactuate both the dogs 70 and 77 carried by the indexing mechanism 47.Thus, on pumping of the assem bly illustrated in FIGURES 2A, 2B, 2C, 2Dand 2E through the nipple 25 located in the tubing string 24, theindexing mechanism 47, as described previously, advances by one count.At this point, should the indexing mechanism have had only one countinstalled thereon initially, the probe 55 will be pulled from theinstallation mechanism 51 and the throw-over mechanism 56 will be incondition to position the gas-lift valve 69 in the next encountered sidepocket 26. However, if the indexing mechanism 47 has more than one countinstalled therein, the

11 probe 55 will not be pulled after the assembly passes through thenipple 25, but rather will be pulled at some subsequent location in thetubing string where the indexing mechanism has counted a number ofcounts equal to the counts initially installed therein.

The side pocket 26 includes a gas-lift valve mandrel 171 disposed at oneend thereof. The mandrel 171 is provided with a latching bore 172adapted to facilitate the locking of a gas-lift valve within themandrel, as will be developed subsequently. The exterior end of themandrel 171 is provided with openings 173 extending therethrough tofacilitate fluid flow through a valve disposed within the mandrel.

The operation of inserting a gas-lift valve 69 into a preselected sidepocket 26 will now be described with respect to FIGURES 6A and 613.Although these figures show only one indexing nipple 25 and side pocket26 in the tubing string 24, the string actually includes a series ofsuch nipples and pockets in spaced longitudinal relationship. The entireapparatus comprising the spaced tool carriers 28 and 38, having theindexing device 47, installation mechanism 51, throw-over mechanism 56,breakaway mechanism 61 and gas-lift valve 69 are connected together andinserted into the flowline 21 (FIG- URE l) at a distant point, such forexample, as a production platform or an installation on shore. A sourceof pressure fluid (not shown) is connected to the flowline 21 in back ofthe apparatus which has been inserted in the line, and the fluid ispumped through the line 21 in back of the tool carrier 28 until it haspassed over the curved section of the fiowline 21 and enters thewellhead assembly where it passes down the tubing string 24. As theapparatus moves downwardly through the tubing string 24, one count isexpended or removed from the indexing mechanism 47 each time it passesthrough an indexing nipple 25. After all the counts have been expended,the indexing mechanism functions to pull the probe 55, thus allowing thedogs 135 (FIGURE on the installation mechanism 51 to move radiallyinwardly under the action of leaf springs 136 so that the throwovermechanism 56 is prepared to expand within the next side pocket 26encountered. As shown in FIGURE 6B, the throw-over mechanism 56 hasexpanded under the action of coil spring 133 to move the gas-lift valve69 into alignment with the preselected mandrel 171. As best shown inFIGURE 5, expansion of thethrow-over mechanism 56 causes the plungerhead 141 to move upwardly within the valve housing 69, thus allowing theupper ends of dogs 142 to move radially outwardly. The apparatuscontinues to move downwardly until the gaslift valve 69 seats within themandrel 171 andthe dogs 142 engage the locking bore 172 to firmly securethe gaslift valve 69 against upward movement out of the mandrel 171.

Circulation is now reversed so that the pressure fluid flows down thetubing string 23 and up through the tubing string 24. The apparatus isextracted from the body of gas-lift valve 69 in the following manner asthe valve 69 is held in position within the locking bore 172 of mandrel171 by the dogs 142. Upward pressure of fluid forces the body member 116 of the breakaway mechanism 61 (see FIGURE 2D) upwardly until thelocking spring ring 149 contacts the shoulder 154 at the top of thegas-lift valve 69. As the body 146 of the breakaway mechanism continuesto move upwardly, the split ring 149 is forced down the tapered shoulder150 until it cont-acts the top of the shear-pin ring 151. An increase inthe fluid pressure causes the shear pins 152, which are preferablybronze or some other soft metal in this operation, to shear and theshear pin ring 151 is initially prevented by the ring 149 from travelingupward, allowing -the split ring 149 to move downwardly relative to thetapered shoulder 150 and contract to a smaller diameter below theshoulder. The ring 151 is then free to move upward out of the top of thevalve member 69 engaged by the ring 153. With the breakaway mechanism 61and plunger free of the valve housing 69, the apparatus moves upwardlythrough the tubing string 24 with the tool carriers 28 and 38 where thisportion of the apparatus can be retrieved at, for example, a wellplatform manifold.

It should be understood that the apparatus could be used to insert agas-lift valve 69 as described above, without using an enlarged headplunger 149. This is due to the fact that dogs 142 carried by thegas-lift valve 69 only lock in the upward direction, and since the valve69 is moving downwardly during the inserting operation there wouldnormally be no chance of the dogs hanging up until the desired sidepocket 26 is reached. However, it might sometimes be necessary toreverse the direction of the apparatus even in the inserting operation,for instance, if a miscount occurred in the indexing mechanism or if oneof the side pockets were fouled, etc. When moving the valve 69 upwardlythrough the tubing string with the dogs 142 expanded, the valve couldeasily hang up such as at a nipple 25 and thus be sheared free from therest of the apparatus and fall to the bottom of the well. Therefore, Iprefer to use the plunger arrangement at 140, 141 as a safety measure tokeep the dogs 142 retracted until the desired side-pocket has beenreached.

Should it be desired to remove a gas-lift valve 69 from one of themandrels 171, the operation would be substantially identical to the onedescribed above. FIG URES 7A and 7B show the apparatus of the inventionmoving toward a gas-lift valve 69 which is to be retrieved from apreselected mandrel 171. The only difference between a retrievingmechanism and that employed to place the valve member 69 in placeoriginally is that a slightly longer plunger head 1613 (FIGURE 9) isattached to the end of the plunger 140, which in this instance may bethreadably secured to member 146, so that the locking dogs 14-2 of thevalve member 69 are retracted out of the locking bore 172 even thoughthe throw-over mechanism 56 is in its expanded condition. Also, in thecase of retrieving the valve 69, the shear pins 152 of the breakawaymechanism 61 are made of steel instead of a soft metal so that they willnot shear. Thus, when circulation is reversed so that the locking springring 149 is forced upwardly into contact with the shoulder 154, acontinued application of fluid pressure raises the entire gas-lift valve69 with its retracted dogs 14-2 out of the mandrel 171 and the entireapparatus is circulated up the tubing string 24 where it may berecovered.

I claim as my invention:

1. An apparatus for installing well tools in one of a series ofidentical pockets disposed laterally of and in communication with theinterior of a well string, said apparatus comprising:

(a) tool carrier means adapted to be pumped through the well string insliding contact with the wall thereof;

(b) a selectively operable installation mechanism operatively associatedwith said carrier means and adapted to be activated to install a tool ina preselected pocket of the well string, said pocket being laterallyoffset from the well string axis in one direction;

(c) an indexing mechanism operatively secured to said installationmechanism and having means for determining the number of pockets bywhich the apparatus has passed; and

(d) actuating means carried by said indexing device and coopera ble withsaid installation mechanism to install the tool in said preselectedpocket of the well string when activated by said indexing mechanism.

2. Apparatus as set forth in claim 1 wherein said installation mechanismincludes a selectively operable throw-over mechanism having means forbiasing said tool 13 into alignment with a preselected pocket of thewell string.

3. A system for installing a tool in one of a series of identicallaterally disposed pockets formed within a well string at longitudinallyspaced locations, comprising:

(a) identical indexing areas located within the well string at each ofsaid pockets, said indexing areas having an internal diameter differentfrom the internal diameter of the well string;

(b) carrier means operatively engaging the tool and adapted to propelsaid tool through the well string;

(c) an indexing mechanism secured to said carrier means and havingsensing means cooperable with said indexing areas to sense the number ofsaid indexing areas through which the indexing mechanism has passed;

(d) a selectively operable installation mechanism operatively associatedwith said indexing mechanism and adapted to be activated to install atool in a preselected pocket of said series of pockets within the wellstring;

(e) said installation mechanism including a normally inactive throw-overdevice havingv means for biasing the tool into alignment with apreselected pocket in the well string; and v (f) actuating means carriedby said indexing mechanism and extending into said installationmechanism is operable engagement with said throw-over device, saidactuating means cooperating with the sensing means of said indexingdevice to actuate the throwover device to bias the tool into alignmentwith a preselected pocket;

(g) said throw-over device further including means extending intooperative engagement with said tool and adapted to release a latchingmechanism carried by said tool upon actuation of said throw-over device.

4. An installation device -for positioning a tool in a pocket disposedlaterally of and in communication with the interior of a well string,said device comprising:

(a) a tubular housing;

(b) a slidable sleeve concentrically arranged within the housing andhaving an outwardly flanged portion extending outside the housing;

(c) resilient means mounted on the exterior of the housing at one endthereof, said resilient means contacting said outwardly flanged portionof the slida ble sleeve to urge said sleeve away from said one end ofthe housing;

(d) releasable dog means mounted on said sleeve for preventing saidresilient means from urging said sleeve away from said one end of thehousing;

(e) a first plurality of toggle links pivotally mounted on said sleeve;and

(f) a second plurality of toggle links pivotally mounted on the otherend of said housing; said toggle links having their free ends pivotallyconnected to each other.

5. A device as set forth in claim 4 wherein said sleeve is provided withan elongated plunger which extends beyond said one end of the tubularhousing for operative engagement with a latching mechanism carried bysaid tool.

6. A method for installing well tools in one of a series of identicallaterally disposed pockets formed within a well string at longitudinallyspaced locations, comprising:

(a) securing a well tool to a tool carrier adapted to be pumped throughthe well string;

(b) pumping said carrier and tool through the well string;

(0) sensing the number of said identical pockets through which the toolcarrier has passed;

(d) biasing the tool into alignment with a preselected one of saidseries of identical pockets;

(e) securing the tool within the preselected pocket;

(f) removing the tool carrier from the tool secured thereto and pumpingsaid carrier to an accessible location remote from said pocket.

7. A method for installing and removing well tools from one of a seriesof identical laterally disposed pockets formed within a well string atlongitudinally spaced l0- cations, comprising:

(a) securing a well tool to a tool carrier adapted to be pumped throughthe well string;

(b) pumping said carrier and tool through the well string;

(0) sensing the number of said identical pockets through which the toolcarrier has passed;

(d) biasing the tool into alignment with a preselected one of saidseries of identical pockets;

(e) securing the tool within the preselected pocket;

( f) removing the tool carrier from the tool secured thereto and pumpingsaid carrier to an accessible location remote from said pocket;

(g) securing a tool retriever to said tool carrier and pumping thecarrier and tool retriever to a location adjacent the pocket;

(h) biasing the retriever into the pocket;

(i) further pumping the carrier through the well string to force theretriever into engagement with the tool disposed within the pocket;

(j) pumping said carrier with the retriever having the tool engagedthereto in a direction to remove said tool from the pocket; and

(k) pumping said carrier and retriever with the tool engaged theretothrough the well string to an accessi'ble location remote from thepocket.

References Cited by the Examiner UNITED STATES PATENTS 2,679,904 6/ 1954Howard et al. 166-66 X 2,776,564 1/ 1957 Montgomery et al. 16664 X2,828,698 4/ 1958 Bryan 166-117.5 X 2,959,227 11/ 1960 Canalizo 116117.53,054,456 9/ 1962 Hammaker 166-45 X 3,111,990 11/1963 Hayes 166643,126,057 3/ 1964 Hayes 166--64 CHARLES E. OCONNELL, Primary Examiner.

ERNEST R. PURSER, Examiner.

R. E. FAVREAU, Assistant Examiner.

1. AN APPARATUS FOR INSTALLING WELL TOOLS IN ONE OF A SERIES OFIDENTICAL POCKETS DISPOSED LATERALLY OF AND IN COMMUNICATION WITH THEINTERIOR OF A WELL STRING, SAID APPARATUS COMPRISING: (A) TOOL CARRIERMEANS ADAPTED TO BE PUMPED THROUGH THE WELL STRING IN SLIDING CONTACTWITH THE WALL THEREOF; (B) A SELECTIVELY OPERABLE INSTALLATION MECHANISMOPERATIVELY ASSOCIATED WITH SAID CARRIER MEANS AND ADAPTED TO BEACTIVATED TO INSTALL A TOOL IN A PRESELECTED POCKET OF THE WELL STRING,SAID POCKET BEING LATERALLY OFFSET FROM THE WELL STRING AXIS IN ONEDIRECTION; (C) AN INDEXING MECHANISM OPERATIVELY SECURED TO SAIDINSTALLATION MECHANISM AND HAVING MEANS FOR DETERMINING THE NUMBER OFPOCKETS BY WHICH THE APPARATUS HAS PASSED; AND (D) ACTUATING MEANSCARRIED BY SAID INDEXING DEVICE AND COOPERABLE WITH SAID INSTALLATIONMECHANISM TO INSTALL THE TOOL IN SAID PRESELECTED POCKET OF THE WELLSTRING WHEN ACTIVATED BY SAID INDEXING MECHANISM.